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Biomedical subjects

S Kannisto

Publications and source records attributed to S Kannisto.

6 recordsLinked to original sources

Serum dehydroepiandrosterone sulfate concentration as an indicator of adrenocortical suppression in asthmatic children treated with inhaled steroids.

ACTH regulates adrenal androgen production, which may thus be reduced during glucocorticosteroid therapy. Dehydroepiandrosterone sulfate is the most abundant androgen secreted by the adrenals. We wished to evaluate whether serum levels of dehydroepiandrosterone sulfate can be used as an indicator of adrenal suppression during inhaled steroid treatment in children. Sixty school-aged children with newly diagnosed asthma were randomly divided into budesonide (n = 30) and fluticasone propionate (n = 30) groups. Fifteen cromone-treated children served as a control group. The budesonide dose was 800 microg/d during the first 2 months and 400 microg/d thereafter. The respective fluticasone propionate doses were 500 and 200 microg/d. Serum dehydroepiandrosterone sulfate concentrations were measured before and after 2 and 4 months of treatment. In the budesonide group, serum dehydroepiandrosterone sulfate decreased from the baseline by a mean of 21% (95% confidence interval, 13-29%; P < 0.001) after 2 months of high dose treatment and by 16% (95% confidence interval, 8-25%; P < 0.001) after 4 months of treatment. In the fluticasone propionate group, the respective figures were 10% (95% confidence interval, 4-16%; P < 0.01) and 6% (95% confidence interval, 16% decrease-3% increase; P = NS). A low dose ACTH test indicated adrenocortical suppression at 4 months in 14 (23%) steroid-treated children. In these children, dehydroepiandrosterone sulfate decreased by a mean of 21% (95% confidence interval, 14-28%), whereas in those 46 steroid-treated children with normal ACTH test results, dehydroepiandrosterone sulfate decreased by 8% (95% confidence interval, 0-16%; P < 0.05 between these groups). In the control group, dehydroepiandrosterone sulfate levels tended to increase (by a mean of 26%), reflecting the normal physiological change at this age. In conclusion, inhaled steroid treatment suppresses dehydroepiandrosterone sulfate production in a dose-dependent manner. Monitoring of serum dehydroepiandrosterone sulfate concentrations can be used as a practical method to follow adrenocortical function and to detect its suppression during inhaled steroid treatment in children.

Administration, Inhalation↗

Evaluation of the interrupter technique in measuring post-exercise bronchodilator responses in children.

A significant response in a bronchodilation test is one of the main diagnostic criteria of asthma. However, it is not known what the significant bronchodilator response (BDR) is by the interrupter technique (IR), measuring respiratory resistance (Rint) during tidal breathing. Fifty children with symptoms suggestive for asthma underwent an 8 min free running test outdoors. Flow-volume spirometry (FVS) and IR measurements were performed before and 10 min after running. Thereafter, all children received a salbutamol inhalation, and pulmonary function measurements were repeated 15 min later. The study population was classified into three groups according to the post-exercise pulmonary function: FEV1 > 100% of predicted (group I, n=15), FEV1 86-99% of predicted (group II, n=20) and FEV1 < 85% of predicted (group III, n=15). There were no differences in BDRs between groups I and II; the mean increases in FEV1 were 4-6% and in MMEF 20-23%, and the mean decreases in Rint were 23-26%. The mean changes in group III were significantly higher: 15% (P=0.004) in FEV1, 55% (P=0.021) in MMEF and 38% (P=0. 014) in Rint. BDR was positive (FEV1 rise >10%) in 15 children; five were in group II and 10 in group III. For MMEF and Rint, the best combination of sensitivity and specificity was achieved by a limit of 35%. By this limit, MMEF identified 14 and Rint 17 positive cases. The IR technique agreed with both FEV1 and MMEF in 73% of the cases. The IR technique provides an alternative to conventional ventilatory function measurements in bronchodilation tests in children. We suggest a decrease of 35% or more in Rint as diagnostic in post-exercise bronchodilation tests.

Adolescent↗

Adrenal suppression, evaluated by a low dose adrenocorticotropin test, and growth in asthmatic children treated with inhaled steroids.

The aim of the present study was to evaluate the prevalence of adrenal suppression and growth retardation in children using moderate doses of budesonide or fluticasone propionate. Seventy-five asthmatic children were randomly divided into three treatment groups: 30 to the fluticasone propionate (FP), 30 to the budesonide (BUD), and 15 to the cromone (CROM) group. FP doses were 500 microg/day during the first 2 months and 200 microg/day thereafter. The respective BUD doses were 800 and 400 microg/day. A low dose ACTH (0.5 microg/1.73 m2) test was performed before treatment and 2, 4, and 6 months later. The test was considered abnormal if the stimulated serum cortisol concentration was more than 2 SD lower than the pretreatment mean (<330 nmol/L). The low dose ACTH test was abnormal after both the high and low steroid doses in 23% of the children. At the 4 month measurement there were more abnormal tests in the BUD (n = 9) than in the FP (n = 5) group (P < 0.05). At that time also the stimulated concentration of serum cortisol was lower in the BUD than in the CROM group (P < 0.01), whereas the difference between the FP and CROM groups was not significant. During the study year the mean decrease in height SD score was 0.23 in the children treated with BUD, 0.03 in the children treated with FP, and 0.09 in the children treated with CROM; the difference between the BUD and FP groups was significant (P < 0.05). In conclusion, the low dose ACTH test revealed mild adrenal suppression in a quarter of the children using moderate doses of inhaled steroids. A FP dose of 200 microg/day caused less adrenal and growth suppression than did a BUD dose of 400 microg/day.

Administration, Inhalation↗

Interrupter technique for evaluation of exercise-induced bronchospasm in children.

The free running test is a useful method for evaluation of exercise-induced bronchospasm in children. In young children this test simulates real-life circumstances and can be done more easily than histamine or methacholine challenges. The interrupter technique is a noninvasive method for measuring airflow resistance during tidal breathing. This approach requires minimal cooperation, and is therefore promising for use in young children. Fifty children aged 5-15 years with asthma symptoms were tested by exercise challenge consisting of free outdoor running for 8 min at 85% of maximal predicted heart rate for age. Pulmonary function was measured by using the interrupter technique (IR), with a Wright's peak flow meter (WPEF), and by flow-volume spirometry (FVS). The measurements were done before and 10 min after exercise. In addition, WPEF was measured at 5, 15, and 20 min after exercise. A fall of 15% or more in WPEF associated with wheezing or cough symptoms was considered a positive test. The exercise challenge was positive in 16 (32%) of the 50 children. Measurements at 10 min by WPEF identified 9 positive cases. At the same time point the IR identified 10 positive cases; a rise in resistance of 15% or more was considered positive, giving it 80% sensitivity and 93% specificity. The repeatability coefficient (CoR) for the interrupter technique was 0.06 kPa x L(-1) x s (13%) before and 0.07 kPa x L(-1) x s (14%) after exercise. The IR provides a useful alternative for estimation of airway obstruction in children following exercise challenge. The results were comparable with the current reference methods of forced expiratory volume in 1 s and peak flow measurements.

Adolescent↗

Use of pocket-sized turbine spirometer in monitoring exercise-induced bronchospasm and bronchodilator responses in children.

For field studies of asthma, portable hand-held pulmonary function testing devices are required. Other than for peak flow measurements, little has been done to validate their use in children. Fifty children aged 5-15 years having asthma symptoms were examined using an exercise challenge (8 min free running outdoors) and a bronchodilation test (salbutamol inhalation at a dose of 0.15 mg/kg). Pulmonary function was measured with a turbine spirometer, with a Wright peak flow meter (WPEF) and with a flow-volume spirometer (FVS). A fall of 15% or more in peak expiratory flow associated with wheezing or cough was considered diagnostic for bronchial hyper-responsiveness to exercise (BHRE). A rise of 15% or more from baseline in peak expiratory flow after salbutamol inhalation was considered as a positive bronchodilator response (BDR). BHRE was present in 16 children (32%). Using the limit of a 15% or greater fall in FEV1, turbine spirometry identified 12 as BHRE-positive and no additional cases, giving a sensitivity of 75% and a specificity of 100%. The turbine spirometer showed lower FEV1 values than the FVS, the difference increasing with airway obstruction. BDR was positive in eight children (16%). Using the limit of a 10% or greater rise in FEV1, turbine spirometry was positive in six cases. FEV1 measured by turbine spirometry could not be used interchangeably with conventional FVS. However, the turbine spirometer offers the possibility to measure FEV1 repeatedly in field conditions, such as during exercise challenges outdoors.

Adolescent↗